Attachment plug



2 Sheets-Sheet 1 ATTACHMENT PLUG Filed July 16 1924 J. C. BLANKENSHIP Jan. 5 1926;

Jan. 5 1926. 1,568,584

J. c. BLANKENSHIP ATTACHMENT PLUG 7 Filed July 16 1924 T 2 Sheets-Sheet 2 as" a2 36 4 @34 n3, -33 D as 39 -34 gwmntu v (Laid/11% J/ZI)? Patented Jan. 5, 1926.

PATENT OFFICE.

JOHN CLARKE BL! NKENSHIP, 01 AUSTIN, TEXAS.

ATTACHMENT IL'UG.

Application filed July 16, 1924. Serial No. 726,312.

To all whom it may concern:

Be it known that I, JoHN C. BLANKEN- SHIP, a citizen of the United States, residing at Austin, in the county of Travis and State I of Texas, have invented certain new and useful Improvements in Attachment Plugs, of which the following is a specification.

This invention relates to attachment plugs and particularly to a device of this character having a base board receptacle for receiving a removable plug havlng a three wa circuit for electrical attachments embo ying the use of a three way ClIClllt Another object of this invention is to provide a base board receptacle and removable plug for use in a three way circuit, particularly adapted for use in connection with a wall switch controlling the lights of a room, so that an auxiliary control switch having a flexible connection with the removable plu for said wall receptacle may be connected in circuit with said wall switch for controlling the lights in the room independently of said wall switch, and in con- 26 junction therewith.

Another object of the invention resides in providing a base board receptacle and removable lug for association therewith connected with the use of a three way circuit,

so including a pair of switches for independently controlling the same circuit so that upon the removal of the plug from the receptacle, disconnecting and rendering one switch inoperative to control said circuit, 86 means is provided for immediately changing the cpnnections of the circuit, upon the withdrawal of the plug, in order that the remaining switch in the circuit may efiiciently control the same, in the usual manner.

The invention comprehends other objects and improvements in the details of construction and arrangement of the parts, more particularly described in the following detailed description and claims, directed to a 4.5 preferred form of the invention, it being understood, however, that various changes in the specific construction and arran ement of these parts may be made without eparting from the spirit and scope of the invention as described and claimed.

In the drawings, forming a part of this application Figure 1 is a vertical sectional view through a portion of a base board in the room of a building equipped with the base board receptacle, orming part of the subject matter of this invention.

Figure 2 is a front view, partly in section of the insulating block carrying the contact which is mounted in the base board.

Figure 3 is a rear view of the same.

Figure 4 is a rear elevational view of a portion of the cover for the box and the contact member carried by the hinge section thereof.

Figure 5 is an enlarged detail sectional view of the removable plug, for use in conunction with said base board receptacle.

Figure 6 ,is a face view of the side of the plug carrying the contact.

Figure 7 1s a die rammatic view illustrating the method 0 wirin the circuit for using this improved form 0 base board receptacle and plug.

1 indicates a portion of a base board in the room of a building, which is formed with an opening for receiving a box or housing 2, in which is mounted an insulatmg block 3, while a cover plate 4 receives suitable screws or other securing means 5, which also extend through portions of the box 2 and extensions on the insulating block 3, for mountin said elements in the base board, in forming a special type of base board receptacle. The box 2 may be provlded with an opening in the rear side thereof for receiving the flexible wire carrying conduit 6, which is secured to said box by a suitable bushing 7, the free edges of the box 2 being provided with projecting tongues 8, formed with openings for receiving the screws 5, and adapted to seat against the outer side of the base board in shallow recesses provided therefor so that the outer faces of the tongues will lie flush with the outer face of the said base board. The insulating block 3 is formed around a bar member 9, which is provided with a plurality of openings 10, through which the material of the insulating block extends for rigidly mounting said bar therein, so that the projecting ends of said bar which are offset and twisted laterally vwith respect to the remainder of the bar as indicated at 11, project be 0nd the ends of the block member 3, an are provided with slotted openings 12 for receiving the screws 5, so that the block member may be conveniently secured and supported in the proper manner in the box 2. A plurality of transversely extending bores 13 are formed in a predetermined manner, in the block member, there being three in number for receiving sleeve sockets 14, which are split at their forward ends and formed with lateral extensions 15, at their rear ends, to be secured and housed Within the enlar ed recesses 16, in the rear face of the bloc in a manner as clearly illustrated in Fi res 1 and 3. Suitable forms of screws 1 are used for securing the extension 15 in the recesses. 16, so that the sleeve contacts are rigidl secured in position in said insulating lock member. A plurality of plates 18 are mounted on the rear face of the block member 3, by suitable forms of screws 19, which receive the wire connections 20 from the respective sleeve contacts. Screws 21 are threadedly mounted in the plates 18 for pro- Y viding a means for removably connecting the ends of the wires 36 thereto.

the circuit wires 22 entering the box 2 from the cable 6, for connecting the contacts car ried by the block member in the circuit, in a desired manner.

The cover 4 for the box and block member is formed with an opening in the central portion thereof as indicated at 23, which is normally closed by a hinged cover section '24, hinged to the cover plate 4, as indicated at 25, a coil spring 26 normally acting to move said cover section 24 to closed position. The rear face of the cover section 24 receives an insulating strip 27 extending diagonally thereon, on which is mounted a contact plate 28 carrying a pair of cylindrical projections 29 adapted to engage in a pair of contact sleeves 14, for closing the circuits between said sleeves, the purpose of which will presently appear.

A removable plug is indicated at 30, which is adapted for association with the wall receptacle and a block 3 which includes a face plate 31, on which is mounted a plurality of contact projections 32, arranged in a predetermined manner, adapted for engagement in the contact sleeves 14. These contact projections are provided on one end with laterally extending seats 33, provided with openings for receiving screws 34 adapted to extend through the face plate 31, for receiving nuts 35 on the inner screw threaded ends thereof, for securing the contacts to the face plate, and also for securing A suitable cover 37 is provided for the face plate which is removably secured thereto, and provided with a sleeve projection 38, for receiving the flexible cable 39, housing the wires 36, and carrying at the free end a three-way switch of pendant form, and of any desired structure well known in the art.

The present invention is adapted for use wherever it is desired, to provide a three- Way circuit with a removable attachment plug for connection with suitable removable apparatus for attachment and one form of such a use is illustrated in the diagrammatic view in Figure 7, in connection with the control of a plurality of 1i hts indicated diagrammatically'at 40, whic are supplied from a suitable source of power 41. The lights, for instance, may represent those in the lighting fixtures of a room of a building, adapted for control by a three-way wall switch, indicated dia ammatically at 42, which is preferably 0? the usual push button type, as generally used, although it may be of any other desired type known to the art. This three-way switch is connected in circuit with the lamps 40 and the source of power, and also the contacts 14 in the block member 3, insulated diagrammatically at 43, in Figure 7, while 44 indicates, diagrammatically the contact bar 28, which is adapted to close the circuit between two of the sleeve contacts 14, in the manner as illustrated by the dotted lines in Figure 7, in order that the wall switch 42 may control the lights 40 in the room, when no attachment is made with the wall receptacle 43. If it is desired to provide another switch for controlling the lights 40, which may be only a temporary one, the plug 30, which is indicated diagrammatically at 45, in Fi re 7,

is inserted into the wall receptacle, with the PI'OJGCtlDg contacts 32 in engagement with the sleeve contacts 14, the cover section 24 hav ng been moved outwardly to an open posltion for permitting the insertion of the plug. The pendant three-way switch above referredto is indicated diagrammatically at 46, in Flgure 7, from which it will be seen that when the plug 45 is in electrical connection with the wall socket, both the wall swltch 42 and the pendant switch 46 will independently control the lights 40, through the three way circuit connecting said switches with said lights and the source of power. It will thus be seen that an attachment may be provided for controllin the lights in a bedroom, which will provide a switch having a flexible connection adapted to be attached to the bed, or supported near the same, so that an occupant of the room upon retiring may extinguish the lights in the room from the bed regardless of the position of the wall switch, and that the control of the lights in the room may be effected by the operation of the wall switch in the usual manner. If it is subsequently desired to remove the plug from the wall or base board receptacle, it will be seen that upon removal 0 the plug from said receptacle, the spring 26 will immediately close the cover section 24 so that the contacts 29 will engage a pair of the sleeve contacts 14 and close the circuit between a pair of the contacts of the base board receptacle, in

order that the wall switch 42 will still be operative for effecting the control of the lights 40.

\Vhile many other uses for this type of attachment plug obviously present themselves, it is believed sufficient to clearly illustrate the invention with the above use, although it is to be readily understood that the invention is not to be limited specifically to the application above described.

What is claimed is:

1. A three-way attachment receptacle comprising a casing adapted for mounting in the base board of a room, a block member positioned and housed in said casing, three contacts mounted in staggered relation in said block for receiving connectionfrom a three wire circuit, said block being adapted to receive a plug adapted for removable con nection therewith having three contacts for engagement with the contacts of said block for interposing desired attachments in the three-way circuit, and means for converting the three-way circuit connected with the contacts of the block into a two-way circuit, said means being adapted for engagement with the contacts of said block when the plug is detached therefrom.

2. 'A three-way attachment receptacle comprising a casing adapted for mounting in the base board of a room, a block member positioned and housed in said casing, a bar member embedded in said block having the end portions projecting beyond the block and the free edges of the casing, and formed with openings registering with openings formed in rib extensions from the easing, said block having three contacts mounted therein in staggered relation for receiving connections from a three-wire circuit, said block and contacts being adapted to receive a plug therein for removable attachment thereto provided with three contacts for engagement with the contacts in the block for interposing desired apparatus in the three-wire circuit, a cover for said casing and block having a hinged section overlying the block, and a contact bar mounted on said hinged section adapted to establish electrical connection between a pair of said contacts in said block converting the three wire circuit into a two wire circuit when the cover section is in closed position, the plug being adapted to hold the cover in open position when connected with said block.

In testimony whereof I afiix m signature.

JOHN CLARKE BLANK NSHIP. 

